Method of forming polycrystalline silicon layer on substrate and surface treatment apparatus thereof

Abstract

A method of forming a polycrystalline silicon thin film includes irradiating an amorphous silicon layer with laser light of an excimer laser energy density of 100 mJ/cm2 to 500 mJ/cm2, preferably 280 mJ/cm2 to 330 mJ/cm2, and a pulse width of 80 ns to 200 ns, preferably 140 ns to 200 ns, so as to directly anneal the amorphous silicon layer and form a polycrystalline silicon thin film. The total energy of the laser used for the irradiation of excimer laser light is at least 5 J, preferably at least 10 J. The laser device includes an homogenizer movably mounted at the end of the optical path of the laser beam.

What is claimed is: 
     
       1. A surface treatment apparatus comprising: an illumination station having an associated x-axis and a y-axis orthogonal to the x-axis;   a laser oscillator emitting laser light along a first optical path in an x-axial direction;   an attenuator provided in the first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator including a first reflection mirror provided in said first optical path of said laser light passing through said attenuator and reflecting light in a y-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror and reflecting light in an x-axial direction along a third optical path parallel to said first optical path;   a third reflection mirror provided in said third optical path and reflecting light in a z-axial direction orthogonal to said x-axial and y-axial directions along a fourth optical path toward said illumination station;   a first rail on which said second reflection mirror is mounted aligned with said third optical path;   a first support mounted for reciprocal movement along said first rail supporting said third reflection mirror and a beam homogenizer;   a second rail aligned with said second optical path; and   a second support mounted for reciprocal movement on said second rail supporting said first rail;   said beam homogenizer provided in the fourth optical path of said laser light reflected by said third reflection mirror;   a chamber provided at the illumination station in a position irradiated by said laser light passing through said beam homogenizer; and   a stage supporting a workpiece and provided at a position irradiated by said laser light incident into said chamber.   
     
     
       2. A surface treatment apparatus as defined in claim 1, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       3. A surface treatment apparatus as defined in claim 1, further comprising a first drive unit for causing reciprocal movement of said first support along said first rail and a second drive unit for causing reciprocal movement of said second support along said second rail. 
     
     
       4. A surface treatment apparatus as defined in claim 1, wherein a condenser lens, a reticle and a projection lens are provided in said fourth optical path of said laser light passing through said beam homogenizer. 
     
     
       5. A surface treatment apparatus as defined in claim 1, wherein a condenser lens, a reticle, and a reflection optical system are provided in said fourth optical path of said laser light pass through said beam homogenizer. 
     
     
       6. A surface treatment apparatus as defined in claim 1, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; an output controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   a voltage controller receiving instructions from said output controller and controlling an emission voltage of said laser oscillator.   
     
     
       7. A surface treatment apparatus according to claim 1, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuator.   
     
     
       8. A surface treatment apparatus as defined in claim 1, wherein said beam homogenizer comprises a fly's eye lens provided in said fourth optical path of said laser light and a condenser lens provided in said fourth optical path of the laser light pass through said fly's eye lens. 
     
     
       9. A surface treatment apparatus as defined in claim 1, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of the laser light, a prism having a planar inner side and having an annular inclined face at an opposed side and provided in said fourth optical path of the laser light passing through said beam expander; and a condenser lens for condensing the laser light split by said prism and provided in said fourth optical path of the laser light pass through said prism.   
     
     
       10. A surface treatment apparatus as defined in claim 1, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of said laser light; and a prism having a convex conical face and provided in said fourth optical path of said laser light passing through said beam expander.   
     
     
       11. A surface treatment apparatus as defined in claim 1, further comprising a shutter blocking said laser light for temporarily opening the first optical path of said laser light provided in the first optical path of said laser light. 
     
     
       12. A surface treatment apparatus comprising: an illumination station having an associated x-axis and a y-axis orthogonal to the x-axis;   a laser oscillator emitting laser light in an x-axial direction along a first optical path;   an attenuator provided in the first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator means including a first reflection mirror provided in said first optical path of said laser light passing through said attenuator and reflecting light in a y-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror and reflecting light in an x-axial direction along a third optical path parallel to said first optical path;   a third reflection mirror provided in said third optical path and reflecting light in a z-axial direction orthogonal to said x-axial and y-axial directions along a fourth optical path toward said illumination station;   a first rail on which said second reflection mirror is mounted aligned with said third optical path;   a first support mounted for reciprocal movement along said first rail supporting said third reflection mirror and a beam homogenizer;   a second rail aligned with said second optical path; and   a second support mounted for reciprocal movement on said second rail supporting said first rail;   a first drive unit for causing reciprocal movement of said first support along said first rail;   a second drive unit for causing reciprocal movement of said second support along said second rail;   said beam homogenizer provided in the fourth optical path of said laser light reflected by said third reflection mirror;   a chamber provided at the illumination station in a position irradiated by said laser light passing through said beam homogenizer; and   a stage supporting workpiece and provided at a position irradiated by said laser light incident into said chamber.   
     
     
       13. A surface treatment apparatus as defined in claim 12, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       14. A surface treatment apparatus as defined in claim 12, wherein a condenser lens, a reticle and a projection lens are provided in said fourth optical path of said laser light passing through said beam homogenizer. 
     
     
       15. A surface treatment apparatus as defined in claim 12, wherein a condenser lens, a reticle, and a reflection optical system are provided in said fourth optical path of said laser light pass through said beam homogenizer. 
     
     
       16. A surface treatment apparatus as defined in claim 12, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; an output controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   a voltage controller receiving instructions from said output controller and controlling an emission voltage of said laser oscillator.   
     
     
       17. A surface treatment apparatus according to claim 12, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuators.   
     
     
       18. A surface treatment apparatus as defined in claim 12, wherein said beam homogenizer comprises a fly's eye lens provided in said fourth optical path of said laser light and a condenser lens provided in said fourth optical path of the laser light pass through said fly's eye lens. 
     
     
       19. A surface treatment apparatus as defined in claim 12, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of the laser light, a prism having a planar inner side and having an annular inclined face at an opposed side and provided in said fourth optical path of the laser light passing through said beam expander; and a condenser lens for condensing the laser light split by said prism and provided in said fourth optical path of the laser light pass through said prism.   
     
     
       20. A surface treatment apparatus as defined in claim 12, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of said laser light; and a prism having a convex conical face and provided in said fourth optical path of said laser light passing through said beam expander.   
     
     
       21. A surface treatment apparatus as defined in claim 12, further comprising a shutter blocking said laser light for temporarily opening the first optical path of said laser light provided in the first optical path of said laser light. 
     
     
       22. A surface treatment apparatus comprising: an illumination station having an associated x-axis and an orthogonal y-axis;   a laser oscillator emitting laser light in an x-axial direction along a first optical path;   an attenuator provided in the first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator means including a first reflection mirror provided in said first optical path of said laser light passing through said attenuator and reflecting light in a y-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror and reflecting light in an x-axial direction along a third optical path parallel to said first optical path;   a third reflection mirror provided in said third optical path and reflecting light in a z-axial direction orthogonal to said x-axial and y-axial directions along a fourth optical path toward said illumination station;   a first rail on which said second reflection mirror is mounted aligned with said third optical path;   a first support mounted for reciprocal movement along said first rail supporting said third reflection mirror and a beam homogenizer;   a second rail aligned with said second optical path; and   a second support mounted for reciprocal movement on said second rail supporting said first rail;   a first drive unit for causing reciprocal movement of said first support along said first rail;   a second drive unit for causing reciprocal movement of said second support along said second rail;   said beam homogenizer provided in the fourth optical path of said laser light reflected by said third reflection mirror;   a chamber provided at the illumination station in a position irradiated by said laser light passing through said beam homogenizer; and   a stage supporting workpiece and provided at a position irradiated by said laser light incident into said chamber; and   an alignment means including: a length measuring device determining the position of said beam homogenizer;   a target detector detecting a target formed on said workpiece on said stage and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit performing processing of computations based on a target signal received by said target detector and instructing positional control of said beam homogenizer; and   a drive unit moving said beam homogenizer by drive control signals to said first and second drive units based on positional control signals from said computation processing unit and input concerning the position of said beam homogenizer determined by said length measuring device.     
     
     
       23. A surface treatment apparatus as defined in claim 22, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       24. A surface treatment apparatus as defined in claim 22, wherein a condenser lens, a reticle and a projection lens are provided in said fourth optical path of said laser light passing through said beam homogenizer. 
     
     
       25. A surface treatment apparatus as defined in claim 22, wherein a condenser lens, a reticle, and a reflection optical system are provided in said fourth optical path of said laser light pass through said beam homogenizer. 
     
     
       26. A surface treatment apparatus as defined in claim 22, further comprising an adjustor adjusting laser emission output, said adjust or including a photodetector detecting the intensity of laser light emitted from said laser oscillator; an output controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   a voltage controller receiving instructions from said output controller and controlling an emission voltage of said laser oscillator.   
     
     
       27. A surface treatment apparatus according to claim 22, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuator.   
     
     
       28. A surface treatment apparatus as defined in claim 22, wherein said beam homogenizer comprises a fly's eye lens provided in said fourth optical path of said laser light and a condenser lens provided in said fourth optical path of the laser light pass through said fly's eye lens. 
     
     
       29. A surface treatment apparatus as defined in claim 22, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of the laser light, a prism having a planar inner side and having an annular inclined face at an opposed side and provided in said fourth optical path of the laser light passing through said beam expander; and a condenser lens for condensing the laser light split by said prism and provided in said fourth optical path of the laser light pass through said prism.   
     
     
       30. A surface treatment apparatus as defined in claim 22, wherein said beam homogenizer comprises a beam expander provided in said fourth optical path of said laser light; and a prism having a convex conical face and provided in said fourth optical path of said laser light passing through said beam expander.   
     
     
       31. A surface treatment apparatus as defined in claim 22, further comprising a shutter blocking said laser light for temporarily opening the first optical path of said laser light provided in the first optical path of said laser light. 
     
     
       32. A surface treatment apparatus comprises: a laser oscillator emitting laser light;   an attenuator provided in a first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator provided in a second optical path of the laser light passing through said attenuator and sweeping said laser light from said attenuator to generate scanning laser light;   a beam homogenizer provided in a third optical path of said scanning laser light from said scanning laser light generator means and homogenizing said scanning laser light;   a chamber provided at a position irradiated by said laser light passing through said beam homogenizer;   a stage supporting a workpiece and provided at a position irradiated by said laser light incident into said chamber; and   an adjustor adjusting the laser emission output, said adjustor including: a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuator.   
     
     
       33. A surface treatment apparatus according to claim 32, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       34. A surface treatment apparatus as defined in claim 32, wherein said scanning laser light generator comprises: a first reflection mirror provided in said first optical path of said laser light passing through said attenuator in an x-axial direction and reflecting laser light in a y-axial direction orthogonal to the x-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror;   a first rail on which said first reflection mirror is mounted and provided along the line of the x-axial direction as an optical axis of said laser light reflected by said first reflection mirror;   a first support which is mounted to reciprocally move with respect to said first rail and supporting said second reflection mirror and said beam homogenizer;   a second rail which is provided along a line of the y-axial direction as another optical axis of said laser light reflected by said first reflection mirror; and   a second support which is mounted to reciprocally move with respect to said second rail and supports said first rail.   
     
     
       35. A surface treatment apparatus according to claim 34, further comprising a first drive unit for causing reciprocal movement of said first support along said first rail; and a second drive unit for causing reciprocal movement of said second support along said second rail.   
     
     
       36. A surface treatment apparatus as defined in claim 32, wherein a condenser lens, a reticle, and a projection lens are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       37. A surface treatment apparatus as defined in claim 32, wherein a condenser lens, a reticle, and a reflection optical system are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       38. A surface treatment apparatus as defined in claim 32, wherein said stage comprises x-axis and y-axis stages moveable in two orthogonal axial directions, an x-axial direction drive unit for driving said x-axis stage, and a y-axial direction drive unit for driving said y-axis stage and wherein said apparatus comprises an alignment means, said alignment means including: a length measuring device for determining the positions of the x-axis and y-axis stages;   a target detector for detecting a target formed on said workpiece on said x-axis and y-axis stages and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said x-axis and y-axis stages; and   a drive control unit for instructing movement of said x-axis and y-axis stages to said x-axial direction drive unit and said y-axial direction drive unit based on positional control instructed from said computation processing unit and the positions of said x-axis and y-axis stages determined by said length measuring device.   
     
     
       39. A surface treatment apparatus as defined in claim 32, wherein said apparatus further comprises an aligner, said aligner including a length measuring device for determining the position of said beam homogenizer; a target detector for detecting a target formed on said workpiece on said stage and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said beam homogenizer; and   a drive control unit for instructing movement of said beam homogenizer to said first and second drive units based on positional control instructed from said computation processing unit and the position of said beam homogenizer determined by said length measuring device.   
     
     
       40. A surface treatment apparatus as defined in claim 32, wherein said beam homogenizer comprises a fly's eye lens provided in said third optical path of said laser light and a condenser lens provided in said third optical path of the laser light pass through said fly's eye lens. 
     
     
       41. A surface treatment apparatus as defined in claim 32, wherein said beam homogenizer comprises a beam expander provided in said third optical path of the laser light, a prism having a planar inner side and having an annular inclined face at an opposed outer side and provided in said third optical path of the laser light passing through said beam expander; and a condenser lens for condensing a laser light split by said prism and provided in said third optical path of the laser light pass through said prism.   
     
     
       42. A surface treatment apparatus as defined in claim 32, wherein said beam homogenizer comprises a beam expander provided in said third optical path of said laser light; and a prism having a convex conical face and provided in said third optical path of said laser light pass through said beam expander.   
     
     
       43. A surface treatment apparatus as defined in claim 32, further comprising a shutter blocking said laser light for temporarily opening the optical path of said laser light provided in said first optical path of said laser light. 
     
     
       44. A surface treatment apparatus comprising: a laser oscillator emitting laser light;   an attenuator provided in a first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator provided in a second optical path of the laser light passing through said attenuator and sweeping said laser light from said attenuator to generate scanning laser light;   a beam homogenizer provided in a third optical path of said scanning laser light from said scanning laser light generator and homogenizing said scanning laser light, said beam homogenizer comprising a beam expander provided in said third optical path of the laser light, a prism having a planar inner side and having an annular inclined face at an opposed outer side and provided in said third optical path of the laser light passing through said beam expander, and a condenser lens for condensing the laser light split by said prism and provided in said third optical path of the laser light passed through said prism;   a chamber provided at a position irradiated by said laser light passing through said beam homogenizer; and   a stage supporting a workpiece and provided at a position irradiated by said laser light incident into said chamber.   
     
     
       45. A surface treatment apparatus according to claim 44, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       46. A surface treatment apparatus as defined in claim 44, wherein said scanning laser light generator comprises: a first reflection mirror provided in said first optical path of said laser light passing through said attenuator in an x-axial direction and reflecting laser light in a y-axial direction orthogonal to the x-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror;   a first rail on which said first reflection mirror is mounted and provided along the line of the x-axial direction as an optical axis of said laser light reflected by said first reflection mirror;   a first support which is mounted to reciprocally move with respect to said first rail and supporting said second reflection mirror and said beam homogenizer;   a second rail which is provided along a line of the y-axial direction as another optical axis of said laser light reflected by said first reflection mirror; and   a second support which is mounted to reciprocally move with respect to said second rail and supports said first rail.   
     
     
       47. A surface treatment apparatus according to claim 46, further comprising a first drive unit for causing reciprocal movement of said first support along said first rail; and a second drive unit for causing reciprocal movement of said second support along said second rail.   
     
     
       48. A surface treatment apparatus as defined in claim 44, wherein a condenser lens, a reticle, and a projection lens are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       49. A surface treatment apparatus as defined in claim 44, wherein a condenser lens, a reticle, and a reflection optical system are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       50. A surface treatment apparatus as defined in claim 44, wherein said stage comprises x-axis and y-axis stages moveable in two orthogonal axial directions, an x-axial direction drive unit for driving said x-axis stage, and a y-axial direction drive unit for driving said y-axis stage and wherein said apparatus comprises an alignment means, said alignment means including: a length measuring device for determining the positions of the x-axis and y-axis stages;   a target detector for detecting a target formed on said workpiece on said x-axis and y-axis stages and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said x-axis and y-axis stages; and   a drive control unit for instructing movement of said x-axis and y-axis stages to said x-axial direction drive unit and said y-axial direction drive unit based on positional control instructed from said computation processing unit and the positions of said x-axis and y-axis stages determined by said length measuring device.   
     
     
       51. A surface treatment apparatus as defined in claim 44, wherein said apparatus further comprises an aligner, said aligner including a length measuring device for determining the position of said beam homogenizer; a target detector for detecting a target formed on said workpiece on said stage and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said beam homogenizer; and   a drive control unit for instructing movement of said beam homogenizer to said first and second drive units based on positional control instructed from said computation processing unit and the position of said beam homogenizer determined by said length measuring device.   
     
     
       52. A surface treatment apparatus as defined in claim 44, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; an output controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   a voltage controller receiving instructions from said output controller and controlling an emission voltage of said laser oscillator.   
     
     
       53. A surface treatment apparatus according to claim 44, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuator.   
     
     
       54. A surface treatment apparatus as defined in claim 44, further comprising a shutter blocking said laser light for temporarily opening the optical path of said laser light provided in said first optical path of said laser light. 
     
     
       55. A surface treatment apparatus comprising: a laser oscillator emitting laser light;   an attenuator provided in a first optical path of said laser light emitted from said laser oscillator;   a scanning laser light generator provided in a second optical path of the laser light passing through said attenuator and sweeping said laser light from said attenuator to generate scanning laser light;   a beam homogenizer provided in a third optical path of said scanning laser light from said scanning laser light generating means and homogenizing said scanning laser light, said beam homogenizer comprising a beam expander provided in said third optical path of said laser light and a prism having a convex conical face and provided in said third optical path of said laser light passed through said beam expander;   a chamber provided at a position irradiated by said laser light passing through said beam homogenizer; and   a stage supporting a workpiece and provided at a position irradiated by said laser light incident into said chamber.   
     
     
       56. A surface treatment apparatus according to claim 55, wherein said laser oscillator emits laser light of at least 2 J/pulse or at least 2 W. 
     
     
       57. A surface treatment apparatus as defined in claim 55, wherein said scanning laser light generator comprises: a first reflection mirror provided in said first optical path of said laser light passing through said attenuator in an x-axial direction and reflecting laser light in a y-axial direction orthogonal to the x-axial direction along a second optical path;   a second reflection mirror provided in said second optical path of said laser light reflected by said first reflection mirror;   a first rail on which said first reflection mirror is mounted and provided along the line of the x-axial direction as an optical axis of said laser light reflected by said first reflection mirror;   a first support which is mounted to reciprocally move with respect to said first rail and supporting said second reflection mirror and said beam homogenizer;   a second rail which is provided along a line of the y-axial direction as another optical axis of said laser light reflected by said first reflection mirror; and   a second support which is mounted to reciprocally move with respect to said second rail and supports said first rail.   
     
     
       58. A surface treatment apparatus according to claim 57, further comprising a first drive unit for causing reciprocal movement of said first support along said first rail; and a second drive unit for causing reciprocal movement of said second support along said second rail.   
     
     
       59. A surface treatment apparatus as defined in claim 55, wherein a condenser lens, a reticle, and a projection lens are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       60. A surface treatment apparatus as defined in claim 55, wherein a condenser lens, a reticle, and a reflection optical system are provided in said third optical path of said laser light pass through said beam homogenizer. 
     
     
       61. A surface treatment apparatus as defined in claim 55, wherein said stage comprises x-axis and y-axis stages moveable in two orthogonal axial directions, an x-axial direction drive unit for driving said x-axis stage, and a y-axial direction drive unit for driving said y-axis stage and wherein said apparatus comprises an alignment means, said alignment means including: a length measuring device for determining the positions of the x-axis and y-axis stages;   a target detector for detecting a target formed on said workpiece on said x-axis and y-axis stages and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said x-axis and y-axis stages; and   a drive control unit for instructing movement of said x-axis and y-axis stages to said x-axial direction drive unit and said y-axial direction drive unit based on positional control instructed from said computation processing unit and the positions of said x-axis and y-axis stages determined by said length measuring device.   
     
     
       62. A surface treatment apparatus as defined in claim 55, wherein said apparatus further comprises an aligner, said aligner including a length measuring device for determining the position of said beam homogenizer; a target detector for detecting a target formed on said workpiece on said stage and arranged at a position enabling irradiation of detection light to said target;   a computation processing unit for performing processing of computations based on a target signal received by said target detector and instructing positional control of said beam homogenizer; and   a drive control unit for instructing movement of said beam homogenizer to said first and second drive units based on positional control instructed from said computation processing unit and the position of said beam homogenizer determined by said length measuring device.   
     
     
       63. A surface treatment apparatus as defined in claim 55, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; an output controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   a voltage controller receiving instructions from said output controller and controlling an emission voltage of said laser oscillator.   
     
     
       64. A surface treatment apparatus according to claim 55, further comprising an adjustor adjusting laser emission output, said adjustor including a photodetector detecting the intensity of laser light emitted from said laser oscillator; a controller instructing an intensity of laser light corresponding to a change of a signal obtained by said photodetector; and   an attenuator controller receiving instructions from said controller and adjusting an angle of reception of light of said attenuator.   
     
     
       65. A surface treatment apparatus as defined in claim 55, further comprising a shutter blocking said laser light for temporarily opening the optical path of said laser light provided in said first optical path of said laser light.